Researchers capture faint antineutrino glow from a shut-down nuclear reactor
Physicists have recorded the weak antineutrino emission that persists after a nuclear plant is turned off, confirming theoretical predictions.
A team from the Double Chooz collaboration has, for the first time, directly measured the lingering antineutrino flux from a de-commissioned nuclear reactor. The underground detector, situated roughly 400 metres from the Chooz plant’s two cores, recorded roughly 100 candidate events during a 17.2-day period when both reactors were completely shut down. The observed rate aligns closely with simulations that incorporate the remaining inventory of long-lived fission products in the core and adjacent spent-fuel cooling pools.
Lead authors Anthony Onillon and Thierry Lasserre of the Max-Planck-Institut für Kernphysik highlighted that the achievement required exceptionally low background levels and refined analysis techniques. Parallel efforts, such as those presented by JUNO-TAO at Neutrino 2026, are also probing reactor-off antineutrino signals. The findings suggest that antineutrino detectors could eventually serve as independent tools for verifying reactor status and tracking spent-fuel inventories during maintenance or after shutdown.
Why it matters
It shows a new way to monitor nuclear reactors and spent fuel even when they are not operating.
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